As the central accumulation area of the Loess Plateau in Shaanxi Province, China, Loess landslides occur frequently, which seriously affect the safety of people’s lives and properties. The prediction and early warning of landslides are the hot spots of geological disaster research, and the prediction of the stability of Loess landslides can provide a reference basis for the prevention and management of landslides. This study takes a typical Loess landslide site in Ganquan County, Yan’an City, as the research object. By collecting soil samples from the landslide body for indoor simulation tests and analyzing and testing the changes in the basic physical and mechanical properties of the soil under different plant root densities and different precipitation conditions, the stability of shallow Loess landslides on the Loess Plateau was simulated using Geo-Studio software. The analysis shows that the stability coefficient of the natural root density of Zhangzi slope soil is 0.889, which belongs to the unstable state, and under the condition of 1.5 times root density, its stability coefficient increases to 1.246, which belongs to the stable state, while at 2 times root density, its stability coefficient decreases to 0.973, which belongs to unstable state, and the stability of its root-soil complex is 1.5 times root density > 2.0 times root density > natural root density. Under different soil water content conditions, the stability of the slope shows a trend of decreasing with increasing water content. Under the condition of 10% soil water content, the stability coefficient of the landslide slope is 1.123, which is the basic stability state; under the condition of 20% soil water content, the stability coefficient drops to 0.886, which is the unstable state; under the condition of 30% soil water content, the stability coefficient is 0.724, which indicates that precipitation has a great influence on the stability of Loess landslides.